During the loading and unloading of ships and barges which involves granular or powder-like cargos, dust laden air escapes periodically from the cargo hole and may be blown considerable distances into the surrounding environment. Such fugitive dust creates serious air pollution problems in urban port location and thus the fugitive dust must be contained if the marine terminal wants to continue its operation. The size of the cargo hold in ships and barges and the variables created by their differing dimensional openings as well as the influence of crosswinds, cause problems for the marine terminals in successfully containing the fugitive dust using any type of present day dust collection equipment.
Various approaches have been proposed in an attempt to contain these fugitive dust particles during ship and barge unloading operations. Some prior art systems create a vacuum within a discharge conduit which is in the ship's or barge's hold. Other prior art systems provide a vacuum immediately adjacent the loading chutes in an effort to contain the fugitive dust particles. Still other prior art systems enclose the entire area adjacent to a hopper and then contain the fugitive dust particles through the use of air streams and dust collection suction devices. Additionally, other prior art systems create an air curtain across the open hold to contain the dust particles and then, through the use of a negative draft dust collection module, the fugitive dust within the open hold is contained.
While these prior art devices have been somewhat satisfactory in containing the fugitive dust particles, their use has been limited to the specific locations immediately adjacent the loading chutes or they have the problem that the assembly and movement of these devices to the various open holds is a time consuming and complicated process. Thus, there is a need in the art for a fugitive dust collection system which is simple to use and move between the various open holds while at the same time is effective in the containment of the fugitive dust particles in order to limit the damage to the surrounding environment.